Vacuum unobstructed path distillation apparatus



Nov. 30, 1948. 2,455,059

VACUUM UNOBSTRUCTED PATH DISTILLATION APPARATUS I K. c. D.- HICKMAN Filed April 5, 1945 KENNETH c. D. mcifmw INVENTOR BY M ATTORNEY Patented Nov. 30, 194$ VACUUM UNOBSTRUCTED PATH DISTILLATION APPARATUS Kenneth C.

D. Hickman, Rochester, N. Y., assignor to Distillation Products, Inc.,

Rochester,

N. Y., a corporation of Delaware Application April 5, 1945, Serial No. 586,810

9' Claims. (Cl. 202-205) This invention relates to improved vacuum distillation apparatus and, in particular, to vacuum unobstructed path distillation apparatus which is at least partially self-evacuating.

The invention has for its object to provide improved vacuum distillation apparatus, particularly of the unobstructed path distillation type in which the energy contained in the distilling vapors is utilized to assist in the removal of gases from the still. Another object is to provide im-' proved high vacuum unobstructed path distillation apparatus of the centrifugal type. A still further object is to improve the state of the art. Other objects will appear hereinafter.

These and other objects are accomplished by my invention which includes apparatus wherein distilling vapors under vacuum conditions are caused to pass, with gases to be evacuated, into a Venturi-shaped passage where the vapors are condensedand from which passage gases are removed by evacuating pumps.

'In the following description I have set forth preferred embodiments of my invention but it is to be understood these are given by way of illustration and not in limitation thereof.

In the accompanying drawings I have illustrated a preferred embodiment of my invention, wherein:

2 liquid from gutter 26 and numeral 30 designates a conduit for introducing liquid to be distilled onto the inside lower surface ofvaporizing surface 22. Numeral 32 indicates a heater for vaporizing plate 22 which is provided with a reflecting baffle 34, which serves to concentrate ,the heat onto vaporizing surface 22.

Numeral 36 indicates a plurality of hollow condensing lattices which have a streamlined shape and which are positioned inside the vaporizing cone 22 so that there is a converging space 38 between each pair of condensing lattices, the space converging as one passes from the vaporizing surface toward the axis of the apparatus. These condensing lattices are connected together as one integral unit by means of conduits 40 so that cooling liquid flows therethrough in sequence, being introduced into the first lattice of the series through conduit 42 and being withdrawn from the last lattice in the series through conduit M. The condensing lattices are main-, tained in the position illustrated by supporting brackets 46. Numeral 48 designates Jan annular dish, or gutter, positioned below lattices 32 so the liquid draining therefrom falls into the gutter 48. Numeral 50 designates a withdrawal conduit through which liquid flows from gutter- 48' and Fig. 1 is a horizontal section of a vacuum still having self-evacuating features and a rotatable vaporizing surface;

Fig. 2 is a vertical section of lustrated in Fig. 1; and

Fig. 3 is a fragmentary vertical section of the liquid withdrawal means shown in Fig. 2.

Referring to Figs. 1, 2 and 3, numeral 4 designates a cylindrical still casing provided with an integral gas-tight base 8 and a removable gastight cover 8, which cover is provided with an evacuating conduit III which, during operation, is connected to the backing pumps (not shown).

the apparatus 11- Numeral i2 designates a shaft which is rigidly housed in a packed gland and bearing l4 and which is provided at its lower end with a drive pulley IS. The upper end of shaft i2,is provided with a hollow portion i8 which terminates in an outwardly spread flange 20 which is integral with a vaporizing surface 22 which isin the form of a truncated cone. The central portion of 22 is provided with an opening 24 corresponding to the hollow portion l8 in shaft l2. The upper periphery of vaporizing surface 22 is flared outwardly and extends into an annular gutter 2B surrounding the outer periphery. Numeral 23 designates a conduit for withdrawing passes into the hollow portion i8 at the top part of shaft i2; Numeral 52indicates a plurality of holes positioned in the portion of i8 which has the largest diameter, the holes being extended outwardly to form jets '54 which protrude into an annular gutter 56, which surrounds them. Gutter 56 is provided with a withdrawn conduit 58.

In operating the apparatus illustrated in the drawings, conduit II] is connected to a ,source of vacuum, preferably high vacuum. Shaft i2 is caused to rotate by force applied to pulley "5. Heating element 32 is put into operation so as to heat vaporizing surface 22 to vaporizing temperature. Distilland, preferably in degassed condition, is introduced through conduit 30 onto the lower part of plate 22 and cooling fluid is introduced through conduit 42 and withdrawn through conduit 44. Liquid flowing from conduit 30 is caused to flow upwardly over the inside surface of 22 in the form of a thin film by centrifugal force. Duringthis passage the thin film of liquid is heated to distillation temperature and vapors pass from the vaporizing surface 22 into the various converging or Venturi shaped passages between the pairs of lattices 36. The vapors have a high velocity'and their predominating directional component is toward the axis of vapors are continuously replenished or backed up by fresh vapors, gases forced into the Venturi space are thus prevented from returning. The pressure is, therefore, built .up in the center of the apparatus and the gases which are thus pumped into the center of the apparatus are removed through conduit 10.

Condensed vapors on lattices 36 flow by gravity downward into butter 48 and flow thence through conduit 50 into hollow l8 at the top of shaft l2. This liquid is then thrown by centrifugal force through openings 52 and nozzles 54 into gutter 56 and is then withdrawn from the still through conduit 58. Undistilled residue, 1. e., liquid which isnot vaporized during passage over vaporizing surface 22, is thrown by centrifugal force into annular gutter 26 and is removed from the still through withdrawal conduit 28.

The invention has the outstanding advantage that the energy of the distilling vapors, which is ordinarily wasted, is caused to materially assist in the evacuation of the still. In thespecific construction shown centripetal force is caused to assist in this evacuation by positioning the lattices as shown and by rotating vaporizing surface 22 in a counter-clockwise direction. The velocity of rotation thus imparted to the vapors is utilized to cause them to pass with even higher velocity into the converging or Venturi spaces 38. While my invention finds its greatest utility in centrifugal trated, the liquid being introduced as a thin film at the top and undistilled residue being withdrawn from the bottom.

What I claim is: V

1. Vacuum unobstructed path distillation apparatus comprising in combination a vaporizing surface over which distilland is caused to flow in a .thin film, means for heating the vaporizing surface, means for introducing distilland onto the vaporizing surface, means for removing undistilled residue-from the vaporizing surface, a plurality of eondensingelements positioned opposite tothe vaporizing surface and separated therefrom by substantially unobstructed space, the principal condensing surfaces of said elements convergin with respect to each other, as the parts of the element farthest from the vaporizing surface are approached, means for cooling the condensing elements, means for removing condensate from the.

condensing elements and .a conduit for evacuating gases from the space between the vaporizing surface and the condensing elements, which conduit is positioned so that gases passing therethrough must, to a large extent, first pass through the converging spaces between the condensing elements.

2. Vacuum unobstructed path distillation apparatus comprising in combination a vaporizing surface over which distilland is caused to flow in a thin film, means for heating the vaporizing surface, means for introducing distilland onto the vaporizing surface, mearfs for removing undistilled residue from the vaporizing surface, aplurality of condensing elements positioned opposite to the vaporizing surface and separated therefrom by substantially unobstructed space,-whlch elements converge with respect to each other, as theparts of the element farthest from the vaporizing surface are approached, so as to form a plurality of Venturi Jets, means for cooling the condensing elements, means for removing condensate from the condensing elements and a conduit for evacuating gases from the space between the vaporizing surface and the condensing elements, which conduit is positioned so that gases passing therethrough must, to a large extent, first pass through the converging spaces between the condensing elements.

3. Vacuum unobstructed path distillation apparatus comprising in combination a rotatable vaporizing surface over which dlstilland is caused to flow in a thin film by centrifugal force, means for heating the vaporizing surface, means for introducing distiiland onto the vaporizing surface, means for removing undistilled residue from the vaporizing surface, a plurality of condensing elements positioned opposite to the vaporizing surface and separated therefrom by substantially unobstructed space, the principal condensing surfacesof said elements converging with respect to each other as the parts of the element farthest from the vaporizing surface are approached, means for cooling the condensing elements, means for removing condensate from the condensing elements and a conduit for evacuating gases from the space between the vaporizing surface and the condensing elements, which conduit is positioned so that gases passing therethrough must, to a large extent, first pass through the converging spaces between the condensing elements.

4. High vacuum unobstructed path distillation apparatus comprising in combination a rotatable, hollow vaporizing surface over the inside surf-ace of which distilland is caused to flow in a thin film by centrifugal force, means for heating the vaporizing surface, means for introducing distilland onto the vaporizing surface, means for removing undistilled residue from the vaporizing surface, a plurality of condensing elements positioned within the vaporizing surface and separated therefrom by substantially unobstructed space, the principal condensing surfaces of said elements converging with respect to each other as the parts of the element farthest from the vaporizing surface are approached, means for cooling the condensing elements, means for removing condensate from the condensing elements and a conduit for evacuating gases from the space between the vaporizing surface and the condensing elements, which conduit is positioned so that gases passing therethrough must, to a large extent, first pass through .the converging spaces between the condensing elements.

5. High vacuum unobstructed path distillation apparatus comprising in combination a rotatable vaporizing surface having the form of a truncated cone over the inside surface of which distilland is caused to flow in a thin film by centrifugal force, means for heating the vaporizing surface, means for introducing distilland onto the vaporizing surface, means for removing undistilled residue from the vaporizing surface, a plurality of-condensing elements positioned inside and opposite to the ment farthest from the vaporizing surface are approached and thus cooperate to form a plurality of Venturi jets, means for cooling the condensing elements, means for removing condensate from the condensing elements and a conduit for evacuating gases from the space between the vaporize ing surface and the condensing elements, which conduit is positioned so that gases passing therethrough must, to a large extent, first pass through the converging spaces between the condensing elements.

6. High vacuum unobstructed path distillation apparatus comprising in combination 'a rotatable vaporizing surface having the form of a vertically positioned truncated cone, up the inclined inside walls of which distilland is caused to flow in a thin film by centrifugal force, means for heating the vaporizing surface, means for introducing distilland onto the inside of the vaporizing surface, means for removing undistilled residues from the vaporizing surface, a plurality of vertical, stream-lined condensing elements positioned inside the vaporizing surface and separated therefrom by substantially unobstructed space, which elements converge with respect to each other as the axis of the vaporizing surface is approached and thus cooperate to form a plurality of elongated Venturi jets, means for cooling the condensing eyements, means for removing condensate from the condensin elements and a conduit for evacuating gases from the space between the vaporizing surface and the condensing elements, which conduit is positioned so that gases passing therethrough must, to a large extent, flrst pass through the converging spaces between the condensing elements.

7. Vacuum distillation apparatus comprising a closed vessel havin therein an inwardly facing distilling surface over which distilland is caused to flow in a fllm, said distilling surface being disposed about a central space, a plurality of condensing elements also disposed about said central space in generally opposed relation to said 4 distilling surface and being separated therefrom by substantially unobstructed space, the principal condensing surfaces of said condensing elements converging with respect to one another at the side remote from said distilling surface and forming thcrebetween passages of progressively decreasing size leading from the space between said distilling surface and said condensing elements to said central space, and exhaust means including an outlet port disposed adjacent said central space so that gases passing from the space between said distilling surface and said condensing elements to said outlet port must largely pass through said converging passages.

8. Vacuum distillation apparatus comprising a closed vessel having therein a rotatable vaporizing member comprising upstanding annular walls providing an inwardly facing distilling surface over which distilland is caused to flow in a film, an annular condenser disposed inside said vaporizing member in opposed relation to said distilling surface and being separated therefrom by substantially unobstructed space, said condenser having therein a series of openings extending in a direction generally parallel to the principal axis of the annulus, said openings leading from the space between said distilling surface and said condenser to a central space within said annular condenser and having decreasing cross-sectional areas from the outside inward providing a series of Venturi-like passageways connecting said spaces, and exhaust means includin an exhaust conduit arranged contiguous to said central space so that gases passing to said exhaust from the space between said distilling surface and said condenser must largely pass through said Venturi-like passageways with concomitant pumping effects.

9. Vacuum distillation apparatus comprising a closed vessel having therein a rotatable vaporizing member comprising upstanding annular walls providing an inwardly facing distilling surface over which distilland is caused to flow in a film,

an annular condenser disposed inside said vaporizing member in opposed relation to said distilling surface and being separated therefrom by substantially unobstructed space, said condenser having therein a series of vertically-extending,

slot-like openings leading from the space between said distilling surface and said condenser to a central space within said annular condenser, said openings having walls converging toward said central space and being directed at a substantial angle to the radii of the annulus whereby the velocity of rotation causes gases and vapors to tend to travel through said openings from thespace between said distilling surface and said condenser to said central space with concomitant pumping effect, and exhaust means arranged to withdraw gases and vapors from said central space. \I

" KENNETH C. D. HICKMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Date Budlane l June 3, 1947 Certificate of Correction Patent No. 2,455,059. November 30, 1948. KENNETH C. D. HIOKMAN It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 2, line 34, for the word withdrawn read withdrawal; column 3, line 15, for butter read gutter; column 5, line 18, for residues read residue; column 5, line 27, for eyements read elements;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 5th day of April, A. D. 1949.

THOMAS F. MURPHY,

Assistant flmmm'ssioner of Patents. 

